We're building a JavaFX application in Windows.
I've tried to use JNA Native.getComponentPointer() method which works with java.awt.panel, but I can't figure out a good way to do this with a javafx.scene.layout.Pane
Does anyone know of any way to do get hWnd for a Pane ?
Unfortunately, I do not think that this is possible with JavaFX. The only thing that I can see that has a native peer is the Stage. You can verify this yourself by using a ui analyzer tool, such as WinSpy, or "inspect.exe" or "visualuiaverifynative.exe" from the Windows SDK.
From Mixing Heavyweight and Lightweight Components by Oracle:
There are two kinds of graphics components in the Java programming language: heavyweight and lightweight. A heavyweight component is associated with its own native screen resource (commonly known as a peer). Components from the java.awt package, such as Button and Label, are heavyweight components.
[...]
A lightweight component has no native screen resource of its own, so it is "lighter." A lightweight component relies on the screen resource from an ancestor in the containment hierarchy, possibly the underlying Frame object. Components from the javax.swing package, such as JButton and JLabel, are lightweight components.
In this case, JavaFX is just like Swing; a lightweight toolkit where the various ui components are all written in Java and do not have a native peer.
As far as my reading of the doc goes, there is a 1:1 relationship between an hWnd and a window object. Panes and Nodes aren't Windows, so trying to get an hwnd specific node doesn't seem to make a lot of sense.
The most you could ask for is the hwnd of the window containing the node. See:
How can I get the window handle (hWnd) for a Stage in JavaFX?.
Applying the function from the answer to the linked question gets:
Pointer hwnd = getWindowPointer(node.getScene().getWindow());
Related
While java programs are platform independent, the JVM itself is platform dependent. I am interested in knowing how Java draws the application GUI (buttons and text) on the screen.
Under Windows, control objects such as buttons are usually created using a window(from user32.dll) or a rectangular region(from gdi32.dll), text is drawn later to the corresponding window/region handle using the provided user32/gdi32 text draw functions.
I tried running a simple two button Java gui application using swing and hooking the majority of create region/window and text draw functions from gdi32.dll and user32.dll, but so far, it seems the Java program is just using these native dlls for drawing the main window frame only.
Does Java.exe uses some other dlls to draw buttons and other controls on the screen ? And if so, why is this case when there are already available native dlls for drawing ?
On Windows Java2D uses Direct3D renderer to draw primitives by default. You may disable it by specifying -Dsun.java2d.d3d=false. In this case GDI renderer will be used.
Add -Dsun.java2d.trace=log,verbose option to trace which Java2D primitives are called in your Swing application.
From the Wikipedia Article:
Unlike AWT components, Swing components are not implemented by platform-specific code. Instead, they are written entirely in Java and therefore are platform-independent. The term "lightweight" is used to describe such an element.
JFrame is Extending Frame. Then, How JFrame is lightweight but Frame is heavyweight?
I red this article but still i didn't get how JFrame achieves its lightweight property?
I got from here that JFrame is heavyweight but other Components starts with J* are lightweight. How other Swing components achieves this. I need bit of technical details.
Technically it's not. Both are heavy weight components, but because JFrame has been setup to support the JRootPane, which contains the content pane (and possibly) the glass pane (as well as the JMenuBar), it is consider "light weight", because it's been deliberately configured to support light weight components
Essentially JFrame and JWindow have been modified as light weight containers that support light weight components
it is still a heavyweight component because it(JFrame) inherits from the Frame.And it is not belong to the JComponents which is lightweight components.
Heavyweight means each Java component has a native peer associated with it. A native peer is an OS-specific component... AWT is heavyweight, so if you create a AWT Button, on the Windows platform an MFC button is created, on *nix a Motif button is created, etc.
Lightweight means that there is not a native peer associated with the java component. This is done by having only the top-level component be heavyweight and all the lightweight components are drawn on to it. Swing is lightweight.
Of course, AWT and Swing are specific to standard Java (J2SE). Under J2ME it depends on what sort of device you are using. If you are using a more powerful device, like the Sharp Zaurus, then you have AWT and functionality pretty close to J2SE levels. If you have something like a Java-Enabled cell phone, you don't have all the capabilites that you need for a fully featured GUI, so there are special libraries used for making these applications. You'd need to look at the APIs provided by the device manufacturer most probably.
JFrames are heavyweight, since it's impossible to create a task-view-level window in most OS without creating a "heavy" AWT window. Lightweight components can replace internal widgets with java-based stuff that doesn't require JNI calls, but windows are the special case. JFrame does let you do custom renders, though. Also, if you're using other lightweight stuff, then I suggest using JFrame as well since it makes the rendering more efficient overall than mixing light and heavy components.
It is still a heavyweight component because it(JFrame) inherits from the Frame. And it is not belong to the JComponents which is lightweight components.
This question might not seem very technical but, out of curiosity,I want to know that:
How does bare/raw Swing code written by me, turn into a wonderful graphical application?
For example:
Like when we make a JFrame visible, or when we place a JButton on it. Who makes it happen? OS or Java or JVM.
Who makes the colors come up?
What is the process going on behind the scenes?
I ask this maybe because its the first time in my life that I made a RealWorld graphical application and these questions popped up in my mind!
Thanks in advance!
In Swing, all the GUI components are written entirely in Java and are rendered using Java. For example, JButtons would be drawn by Java and not by any internal OS stuff. Thus, Swing components are called "light-weight components" because they are managed and rendered by Java instead of by the OS (or any native widget toolkit).
Note that Java also has a toolkit called AWT. Swing is based on nested and inherited methods from AWT, except that it creates native widgets using the OS.
So at some point, Swing will have to create a window on the screen and draw on it. The magic that actually creates the window is handled by AWT. Notice that JFrame extends from java.awt.Frame which means that although JFrame may be rendered mostly by Java, it is backed by a heavy-weight native OS window.
In short, there's an AWT toolkit, which is the layer that does all the window management and drawing. It is calling native platform specific code inside the JVM. It is also responsible for java2d drawing. It can use accelerated directx or opengl pipelines.
Swing is developed on top of it. Swing actually draws every button and every object with plain java code. The drawing is handled to a current look and feels that decide how to draw components. So you can override their paint methods, and add some extra things without any problems.
Metal and Nimus LaF are 100% java2d drawn, so inside of them you will find things like drawRectangle and drawLine to draw components. Native look and feels, like windows, gtk, access current operating systems theme to draw something that looks similar to native widgets. That is why they do not always look like native applications.
There are also other gui toolkits for java, like SWT, used, for example, in Eclipse. What it is doing, is getting the window from the AWT, and then putting 100% native widgets on it. It is much better integrated with the OS, looks better, works faster, uses less memory. But with it, you'd have to distribute your application with os specific native libraries and it is less customizable, compared to Swing.
I don't know all the details, but the actual graphics are displayed/rendered via the swing/awt packages through the JVM itself.
I want to make an application which will have the following:
a jframe (or frame, or whatever) with some java style menus (Jmenu) on the side, and on the other side of the jframe, a OpenGL canvas (which only occupies part of the jframe) and let them integrate together.
meaning, for example, I want to change a slide, and it will change the view of the opengl.
Is it even possible to embed an OpenGL inside a Jframe?
Also, a recomandation for an opengl library that would support such thing. I played a bit with JOGL, but also saw that there are other open-source, and also LWGL and stuff
EDIT:
Added an image from a project made with JOGL which is exactly what I'm after.
A canvas of JOGL inside a Java GUI
for hight Graphics performance is required to use AWT Component exclusively,
I'd suggesting not mixing AWT with Swing
maybe JOGL could be right way, maybe not
We have a very large Java Swing desktop application comprising of a great deal of views. Developers have done a pretty good job over the years in choosing appropriate class locations which reflect the general structure of our UI for these views. Most of this time this is very helpful in tracking down specific components that have bugs which need tending to. However, there are cases where finding a panel, dialog, etc is quite painful. It usually involves searching our properties files for unique string sequences that appear in the UI.
Does anyone know of a third-party tool that allows a developer to hook into a Swing application and click on a region of the UI to reveal that name/package/hierarchy of the component that was clicked?
SwingExplorer is the perfect tool for that. It does what you are describing, and even more (step-by-step drawing of Java2D, EDT violations, AWT events).
Does anyone know of a third-party tool that allows a developer to hook into a Swing application and click on a region of the UI to reveal that name/package/hierarchy of the component that was clicked
Darryl's Component Tree Model should provide you with this basic information. The demo shows how you would use the root pane as the container for viewing all the components. You would need to add a MouseListener to your application to get the Container that was clicked so you could display the component tree.
There's something doing exactly what you're looking for in the SwingX Demo. The JXTreeTable demo contains a tree of the components hierarchy, when the mouse rolls over a particular component, it is selected in the table.
You can have a look here
Couldn't believe it myself, but it could be really as easy as:
SwingUtilities.getRoot(...).list()
The list method exists since 1.0. lol.